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While doing an experiment, I noticed a slight bump in the cooling curve. I have searched for it on the internet and all of the articles say that it is something related to super-cooling.

The graph's bump is shown below: enter image description here

X Axis is time, Y Axis is the temperature.

What is the specific reason for this?

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    $\begingroup$ Since there is absolutely no detail in the graph, I'm going to assume that the x-axis is measured in elephants and the y-axis in mouses. In which case, I would have to say that I'm not sure how mouses and elephants have to do with supercooling or cooling in any way. $\endgroup$
    – Kyle Kanos
    Sep 19 '15 at 11:27
  • $\begingroup$ Hahahaha! After reading that comment, I was smirking in my class; I am so sorry for not mentioning that, I thought I had it on the image, but since I didn't see the preview, that happened. $\endgroup$
    – weirdpanda
    Sep 19 '15 at 13:10
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    $\begingroup$ @weirdpanda: Laugh all you want but without an accurate description of the experiment no one here will be able to throw some light on your bump. Personally I do have an idea what it might be but I won't make a fool of myself by speculating on such little information. $\endgroup$
    – Gert
    Sep 19 '15 at 13:47
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Yes, it is (probably) caused by supercooling.

You might be interested to have a look at this Google search to see lots of similar examples. From this search I found this article that gives a nice description - see the section titled Solidification. The figure they show is:

Supercooling

which is obviously similar to your cooling curve.

What happens is that the liquid cools to below the freezing temperature. The liquid to solid transition releases heat - when a mass $m$ of the liquid freezes the heat released is $Lm$ where $L$ is the latent heat of fusion. When solidification of the supercooled liquid starts this released heat pushes the temperature up again. Hence the dip and rise in the cooling curve.

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  • $\begingroup$ Thanks a lot. That was probably what I was looking for! :) $\endgroup$
    – weirdpanda
    Sep 20 '15 at 9:49

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